The purpose of this project is to provide consultative services in statistical and epidemiological methodology in the design, interpretation, and evaluation of clinical trials and other studies requiring this kind of expertise. For some trials the Section provides full statistical support including development of detailed study plans, randomization of patients, collection, processing editing, and analysis of data, and preparation of scientific papers. At present, members of the Section are involved in studies concerned with prostate cancer, bladder cancer, testis cancer, breast cancer, lung cancer, brain tumors, mycosis fungoides, and Burkitt's lymphoma. Other important work has included an analysis of the predictive value of animal tumor models used in screening potential chemotherapeutic agents, and analysis of several studies dealing with skin test antigens and tumor markers designed to evaluate their potential both in diagnosing cancer and in following its course after treatment. In addition to these major projects, a variety of other consultative activities, including review of scientific articles, arise in response to special requests.